Re: being clearer about css-wide keywords and reset-only sub-properties [css-cascade][css-grid][css-border]

On Sat, Nov 28, 2015 at 9:03 PM, L. David Baron <dbaron@dbaron.org> wrote:
> On Saturday 2015-11-28 17:21 -0800, Tab Atkins Jr. wrote:
>> On Tue, Nov 17, 2015 at 7:51 AM, L. David Baron <dbaron@dbaron.org> wrote:
>> > I think this points to lack of clarity in the spec wording, given
>> > that the definition I quote above in css-cascade is not findable
>> > from the definitions of these reset-only sub-properties.  I think
>> > that the prose defining these reset-only sub-properties in css-grid,
>> > css-border, etc., should:
>> >
>> >   1. link to the definition of the term "reset-only sub-property" in
>> >      css-cascade
>> >
>> >   2. either (a) be more deferential to that definition about what it
>> >      means (and not state that the properties are reset to initial
>> >      values) or (b) explicitly mention that CSS-wide keywords are
>> >      applied rather than resetting those subproperties to their
>> >      initial values (as all other values of the shorthand do).  Or,
>> >      to put it another way, spec prose should not state that most
>> >      values reset the subproperty to its initial value without also
>> >      stating that the css-wide keywords do otherwise.
>>
>> The css-wide keywords are never present in the grammars, and thus
>> never described in the definitions of the property.  They're defined
>> for all properties in Cascade in a uniform manner - they get expanded
>> out to themselves for all subproperties. I don't really want to have
>> to remember to include boilerplate in the description of every
>> shorthand reminding people that the css-wide keywords exist and how
>> they work; that's extra work, and provokes extra confusion when it's
>> forgotten and people try to infer a difference from the lack.
>
> I'm not saying that something needs to be done for every shorthand.
> I'm saying that it needs to be done when properties are defined as
> reset-only subproperties.
>
> Lax wording defining reset-only subproperties has been taken to
> trump the general rules by multiple implementors who work on
> different engines:
>   https://code.google.com/p/chromium/issues/detail?id=557159#c5
>   https://bugzilla.mozilla.org/show_bug.cgi?id=1176792#c40 (and #c39)
> so this is in fact a real problem.

I believe you, I'm just trying to make sure we hit on a solution
that's maximally likely to be done by spec editors. Copy/pasted
boilerplate is very bad in this regard.

"Reset-only sub-property" is a dfn'd term in Cascade; do we just need
to be better about autolinking that when defining such properties?

~TJ

Received on Tuesday, 1 December 2015 04:28:34 UTC